The present invention relates to a process for winding, on a take-up shaft, a sheet material fed from a supply source, which process consists in taking up the sheet of material on an idler shaft and in driving this take-up shaft by means of a bearing drive cylinder rotating at the same linear speed as the feeder.
It may be, for example, a strip of material, such as a sheet of aluminum, paper, cardboard etc., coming from a wider strip cut longitudinally.
In the processes known at present, the strip is most often taken up on a drive shaft. Such driving at the center of the spool which is formed tends to constrict the successive turns of material, causing an uneven spool to be obtained.
Furthermore, it is necessary to continually readjust the rotational speed of the take-up shaft as the diameter of the spool which builds up increases.
To palliate these disadvantages, it has been proposed, for example in the German Pat. No. 578 713, to drive the spool which builds up by the periphery thereof.
In this case, the spool is driven by a roller bearing on its periphery. This roller is itself driven at the same speed as a feeder, formed from two drums between which the strip passes, a chain connection joining together the shaft of one of the drums of the feeder and the shaft of the roller.
With such a device, theoretically, the absence of drive at the center of the spool which builds up eliminates the irregularities in tightness of the turns.
Moreover, there is no longer an increase of torque to be compensated for since the diameter of the drive cylinder does not vary.
Means are not provided for acting solely on the roller in order to re-establish the identity of linear speed between this latter and the feeder, such identity being affected by such factors as the section or the nature of the driven material.